How to take macro photos in tele range with Rebel XT and sigma 70-200

[timezone123]

I am using canon digital rebel XT(350D) with Tamron AF 28-75mm f/2.8 XR Di IF macro and Sigma 70-200mm f/2.8 EX DG APO Macro HSM . How do I take a macro photo of a persons face who is standing say some 10 feets away(or how do I take a macro in tele range)?

Earlier I had Tamron AF70-300mm F/4-5.6 Di LD Macro 1:2 which had a macro switch on the lens and if I switch that on from 180-300mm it would give macro shots in tele range. But although the Sigma lens has macro label on it, there is no macro switch or anything like that? Please help.

[VTEC_EATER]

Macro just means that the lens can focus when closer to the subject.

The regular version of the Sigma 70-200 F/2.8 has a minimum focus distance of 180 cm. Your "Macro" version has a minimum focus distance of 100 cm.

If you are 10 feet away, both lenses will take the same picture.

[timezone123]

Macro just means that the lens can focus when closer to the subject.

The regular version of the Sigma 70-200 F/2.8 has a minimum focus distance of 180 cm. Your "Macro" version has a minimum focus distance of 100 cm.

If you are 10 feet away, both lenses will take the same picture.

Oh, I see. Now I understand why I was getting pictures with sharp background. Thanks a lot for that.

If I want to take a persons picture who is 10 feet away and with the whole background blurred, then what settings shall I use? (as you can see, I am a newbie. Sorry if I am too silly)

Timezone

[coldrain]

What makes teh backgroud blurry is a shallow depth of field. To accomplish a shallow depth of field you must choose a big aperture (small f-stop number).
Put your camera in Av mode, and experiment with different aperture settings.
F2.8 will give the most blurry background, bigger settings will show more and more things in focus.